Not Applicable
Not Applicable
1. Field of Invention
This invention relates to friction drive transmissions.
2. Description of Prior Art
Present and prior walk-behind lawnmowers that use large rear wheels (commonly referred to as high-wheel mowers) use a drive system consisting of a rotating cog shaft or driveshaft that directly engages a pair of rear wheels.
In the disengaged position the driveshaft does not contact the rear tires. To engage the drive the driveshaft is moved into the rear tires. The driveshaft is mounted on a pair of bearing supports that pivot on one end to allow for this movement into the rear tires.
Present and prior constructions use a complex belt and roller chain arraignment to rotate the driveshaft and allow for a linear movement of the driveshaft assembly that is required to move the driveshaft into the tires.
The present and prior drive system does not allow for a multiple speed transmission. Changing the ground speed of a mower utilizing this present and prior system requires that the mower be stopped and disassembled to replace certain parts, changing the ratio between rotating parts.
The present system of moving the driveshaft cogs into the wheels does not lend itself to utilization of a friction drive, as a friction wheel must not be moved in a front-rear direction that was heretofore necessary to facilitate engagement between driveshaft and wheel.
I have not found any prior art in the patent records, therefore I have included an informal drawing of the present and prior art FIG. 1.
An engine 36 rotates a main pulley 42 via a main belt 30. This rotation is transferred into a twisted drive belt 44. Twisted drive belt 44 rotates a jackshaft 46. Jackshaft 46 rotates a driveshaft 20 via a drive chain 48. Driveshaft 20 is mounted on a pair of driveshaft supports 50. The lower end of driveshaft supports 50 is allowed to pivot on a pair of pivot bolts 52. A pair of drive cogs 26 are attached directly to driveshaft 20. To propel the mower the entire driveshaft 20 is pulled into a pair of ground engaging wheels 24 via an engagement rod 54; causing the ground engaging wheels 24 to rotate and propel the mower.
20 driveshaft
22 driveshaft bearing
24 ground engaging wheels
26 cog
30 main belt
36 engine
42 main pulley
44 twisted belt
46 jackshaft
48 drive chain
50 driveshaft supports
52 pivot bolts
54 engagement rod
Accordingly, several objects and advantages of the present invention are:
(a) to provide a drive system that will easily allow multiple drive ratios (ground speeds);
(b) to provide a drive system that will allow ratios to be changed while in operation;
(c) to provide a drive system that is simple to manufacture;
(d) to provide a drive system that is easy and simple to use and maintain;
(e) to provide a drive system with fewer moving parts;
(f) to provide a drive system that utilizes a friction drive;
Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
The present invention provides a multi-ratio friction wheel drive system suitable for use on high-wheel lawnmowers and other small vehicles.